There is absolutely nothing evil or wrong about interlacing. It works great, and has been in use for longer than most people on this planet have been alive. It is still used today, and you watch interlaced TV all the time, and it looks wonderful.

That said, it does require more skill and knowledge to work with in the digital realm. In particular, any resizing or change in cadence does require deinterlacing, a step that always degrades the video. But, since re-sizing and frame rate changes ALSO degrade the video, deinterlacing, when used for those operations, isn't necessarily an "evil" thing. (I would advise never to deinterlace for any other reason.)

However, I will agree that interlacing appears to be a bad thing since so many people screw up their video because they don't understand how to handle it properly. This forum is filled with hundreds of posts that perfectly illustrate this point.

As for your request, the answer will depend on what you are trying to do. If you are trying to put it on a DVD, there are some pretty nifty solutions that have been posted in this forum which involve creating some unique pulldown flags. I didn't even know such a thing existed until I "went to school" in this long thread:

Despite the heading, this person wanted to do something very similar to what you are doing. I linked to the post in that thread where I learned something I didn't know, namely that you can use something called DGPulldown to accomplish this feat, without any re-encoding. The result will play on an NTSC DVD player. Some people don't like the solution because it is interlaced (see my comments above) and also because they don't like the effect of pulldown (repeated fields). However, having tried all the other alternatives to pulldown, and since I deal with film transfers every day of my life, it is my opinion that this gives you the best-looking, sharpest results, and without any problems that you get doing speed changes or de-interlacing using motion estimation, bobbing, etc.

I am certainly not going to get into a discussion about whether I'd rather have 60p as a standard rather than 60i. We are not supposed to talk about "better" in this forum, but I think I'm on safe ground saying that we'd all prefer 60p to 60i. However, as an engineer, I understand the fact that broadcast bandwidth, computing horsepower, computer memory, and many other constraints make interlaced video the best way to get a better picture than would otherwise be available to the customer, given these constraints.

It is true that most (but not all) viewing devices do create a "progressive reconstruction" (I like that term) for displaying the result, but I think most of the ones I've seen actually do a remarkably good job compared to 90% (or perhaps 99%) of the attempts to "do it yourself." There are clearly a few people in this forum who know how to do it right, but based on the video people send to me for restoration, I'd say that is the exception, and not the rule.

There is absolutely nothing evil or wrong about interlacing. It works great, and has been in use for longer than most people on this planet have been alive. It is still used today, and you watch interlaced TV all the time, and it looks wonderful.

If it works great for you, cool. I hardly even watch TV, much less interlaced TV, but on the rare occasion I do switch on my television set, I'm greeted with Moiré and shimmer, thanks to interlacing.

My objection isn't so much to deinterlacing (which is a restorative step) as it is to interlacing (which is a destructive step). Without interlacing, deinterlacing wouldn't be necessary. I think I've read papers showing that interlacing doesn't actually save bandwidth when lossy compression is used, but I can't find a link and it's apparently very difficult to search for this because all I get are descriptions of H.264 instead, so maybe I'm misremembering.

Maybe I should conduct some tests of my own when I'm feeling less lazy.

Quote:

Originally Posted by johnmeyer

Some people don't like the solution because it is interlaced (see my comments above) and also because they don't like the effect of pulldown (repeated fields). However, having tried all the other alternatives to pulldown, and since I deal with film transfers every day of my life, it is my opinion that this gives you the best-looking, sharpest results, and without any problems that you get doing speed changes or de-interlacing using motion estimation, bobbing, etc.

I dislike this not because it's interlaced or because it's pulldown; I dislike this because it's unnecessary munging of the video. Maybe use something a bit less ancient than DVDs, like H.264 in Matroska with literally any frame rate you want, and you don't even have to do any destructive operation to your video (other than the lossy compression). Otoh, if you do need it to be a DVD for whatever reason, I second johnmeyer's suggestion.